What is a literary or dramatic speech that is delivered by a solitary character?

The correct answer is a soliloquy. A soliloquy is a specific type of speech in literature and drama where a character speaks their thoughts aloud while alone on stage, allowing the audience to gain insight into their internal struggles, emotions, and motivations. This form of expression is often used to reveal deep personal reflections and is instrumental in character development.

While both a monologue and a soliloquy involve a single character speaking, a monologue can be directed toward other characters or the audience, whereas a soliloquy is specifically characterized by the speaker's isolation from others. Dialogue refers to a conversation between two or more characters, and an aside involves a character speaking to the audience while other characters are present, showcasing a brief moment of inner thought without the same degree of introspection as a soliloquy.